Persistent symptoms and chronic disease
Persistent symptoms deserve a structured medical review.Not a promise of one hidden root cause.
When several symptoms persist or overlap, the useful task is to separate what is diagnosed, what remains unexplained, what needs urgent or specialist assessment and what testing could genuinely change care.
Persistent symptoms need a structured assessment, not a single hidden-cause theory.
Long-lasting symptoms can come from a diagnosed condition, several conditions at the same time, medicine effects, mental-health problems, sleep problems, pain syndromes or symptoms that remain unexplained after reasonable investigation. The fact that a cause has not yet been found does not mean the symptoms are imaginary. [2]
NICE guidance on multimorbidity also recognises that people may live with several physical and mental-health problems at once, and that the burden of treatment itself can become part of the problem. [1]
A useful review therefore starts by defining the problems separately: what is already diagnosed, what remains unexplained, what has changed, what treatment is already in place and which concern is most important now.
What should a review of persistent or overlapping symptoms include?
Start with a timeline. When did each symptom begin? Did several symptoms start together, or did they build up over months or years? What was happening around the time they changed?
Then review existing diagnoses, previous tests, medicines, supplements and specialist letters. This helps prevent two common problems: repeating work that has already been done, and overlooking a known condition because attention has moved to a newer symptom.
Finally, look at function. Which symptoms affect sleep, work, mobility, eating, relationships or daily activity? NICE recommends care that reflects what matters to the person rather than treating every problem as equally important. [1]
What if previous blood tests or scans were normal?
Normal results can be useful because they make some diagnoses less likely, but they do not automatically explain why someone still feels unwell. The next step depends on what was tested, when it was tested, the quality of the test and whether the symptom pattern has changed.
The dedicated guide on what to do when blood tests are normal but symptoms persist goes into this question in more depth. This page keeps the broader task: deciding how several concerns fit together without assuming that one hidden diagnosis must explain all of them.
Repeated testing should answer a clear question. If the result would not change treatment, referral or monitoring, another test may add cost and uncertainty rather than useful information.
How do doctors assess multiple unexplained symptoms?
The NHS describes medically unexplained symptoms as real physical symptoms for which a clear medical cause has not been identified after assessment. Possible explanations may include recognised syndromes such as ME/CFS, IBS, fibromyalgia or functional neurological disorder, and mental-health problems can also coexist. [2]
The multiple unexplained symptoms guide explains this assessment in detail. A structured review can include physical examination, selected blood tests, review of mental health and sleep, and referral when the pattern suggests another specialty.
The absence of one diagnosis is not evidence for an unvalidated alternative diagnosis. Terms such as “toxicity”, “adrenal fatigue” or “chronic inflammation” should not be used as a catch-all explanation unless a recognised condition or validated finding supports the claim.
How should testing be chosen?
Testing should follow the clinical question. The live functional medicine testing and diagnostics page explains the practice’s question-led testing approach and the limits of additional investigation.
Some symptoms may justify standard blood tests or established diagnostic pathways first. Other symptoms may need specialist referral, imaging or observation. A broad private panel is not automatically more informative than a smaller set of tests chosen for a specific reason.
NICE shared-decision guidance says clinicians should explain the aims, risks, benefits and consequences of different options, including choosing no treatment or no change. [3] That principle applies to tests too: the patient should understand what is being looked for and what will happen after the result.
How do medicines and existing specialist care fit into the review?
Existing conventional treatment remains relevant. A new functional-medicine review should not automatically replace medicines, NHS care or specialist plans that are already managing a diagnosed condition.
Bring a complete medicine and supplement list. Side effects, interactions, duplicate products and treatment burden can all contribute to symptoms or make the overall plan harder to manage.
NICE multimorbidity guidance advises balancing the benefits and harms of individual treatments and considering the person’s priorities. [1] If a prescribed medicine may be contributing to symptoms, the safer route is review with the responsible prescriber rather than stopping it independently.
When is referral or a different medical route more appropriate?
A private functional-medicine consultation is not the right route for every problem. A specific symptom pattern may need gastroenterology, neurology, cardiology, rheumatology, psychiatry or another specialty. New or rapidly changing symptoms may need ordinary GP or urgent assessment before a broader review.
NICE shared decision making supports discussing all reasonable options, including referral or no additional intervention. [3] The goal is to choose the route that best answers the clinical question, not to keep every part of care inside one model.
For people comparing provider options, the doctor-led functional medicine service page explains Dr Stavy’s consultation scope, and the first consultation guide explains what happens during the assessment process.
How can you prepare for a persistent-symptoms consultation?
- Bring a short timeline of the symptoms that matter most.
- Bring previous results and specialist letters rather than relying on memory.
- List every prescribed medicine, over-the-counter medicine and supplement.
- Note which symptoms are new, worsening or changing pattern.
- Write down the two or three decisions you most want the appointment to help with.
- Keep emergency and specialist care separate from routine private review.
A clear starting list helps the consultation stay focused. It also reduces the risk that a broad history turns into a long series of tests without a defined purpose.
A simple way to organise a complex health history
Start with three lists. The first list is what has already been diagnosed. The second is what still has no clear answer. The third is what has changed recently.
Keep the lists short. Put the most important problem first. This helps the doctor decide what needs action now and what can wait.
Bring the full names of medicines and supplements. Include the dose if you know it. A medicine can help one condition and still cause a side effect that needs review.
Bring old results too. A normal result can stop a test from being repeated for no reason. An abnormal result can show where follow-up is still needed.
Ask who owns each next step. One problem may stay with your GP. Another may need a specialist. A third may only need review after more time has passed.
This approach does not promise one answer for every symptom. It gives each problem a clear place in the plan.
What can a useful plan look like after the review?
A useful plan is usually short. It may include one or two tests, a medicine review, a referral, a lifestyle change or a period of observation.
Each action should have a reason. You should know what question it is meant to answer. You should also know what happens if the result is normal.
Not every symptom needs a new test. Not every old diagnosis needs to be reopened. Some problems improve when the existing treatment is made simpler or easier to follow.
Set a review point. If a symptom changes before then, seek help sooner. If nothing changes, the planned review can be used to decide whether the current approach is still right.
What patients say about the consultation experience.
Patient reviews can describe Dr Stavy’s consultation style. They do not prove that persistent symptoms share one cause or that a particular test or treatment will help.
Individual reviews reflect personal experiences and do not establish diagnosis, treatment effectiveness or outcome.
“patient, understanding and kind”
Google reviewer
“warm and compassionate bedside manner”
Google reviewer
“takes incredible care to get to know her patients”
Google reviewer
Common questions
Can one hidden problem cause many different symptoms?
Sometimes one condition can affect several body systems, but it is not safe to assume that one hidden cause explains every persistent symptom. Several conditions, medicines, sleep problems or mental-health factors can coexist. A structured assessment separates confirmed diagnoses, unresolved symptoms and new warning signs before deciding what needs investigation.
What if all my previous tests were normal?
Normal results can still be useful because they make some diagnoses less likely. The next step depends on which tests were done, how recent they are and whether symptoms have changed. Repeating the same tests without a new clinical question may add little, while a different pathway or specialist review may be more useful.
Does functional medicine mean stopping conventional treatment?
No. Existing conventional and specialist care should remain visible in the plan. Prescribed medicines should not be stopped simply because a new explanation or complementary approach is being considered. Any medicine change should be reviewed with the responsible prescriber, particularly when the medicine is treating an established condition.
Will I need specialist or advanced testing?
Not necessarily. Testing should be chosen because it can answer a defined question and change a decision. Standard investigations, observation or specialist referral may be more appropriate than an advanced panel. The clinician should explain what a result could mean and what would happen next before a test is ordered.
Can anxiety or depression cause physical symptoms?
Mental-health conditions can contribute to physical symptoms and can coexist with physical disease. That does not make the symptoms imaginary. A complete assessment can consider mood, sleep and stress alongside physical causes, medicines and previous findings, with treatment or referral matched to the problems actually identified.
When should persistent symptoms be assessed urgently?
Do not wait for a routine private consultation if symptoms suggest a medical emergency. Call 999 for life-threatening problems such as severe breathing difficulty, signs of stroke or severe chest pain. Use NHS 111 when urgent medical help is needed and you are unsure which service is appropriate. [4]
Medical sources and further reading
- NICE NG56: Multimorbidity. Guidance on prioritising problems, treatment burden and person-centred care when several conditions coexist. Accessed 29 September 2026.
- NHS: Medically unexplained symptoms. Patient information on persistent physical symptoms without a clear identified cause and recognised overlapping conditions. Accessed 29 September 2026.
- NICE NG197: Shared decision making. Guidance on discussing tests, treatments, alternatives and the option of no intervention. Accessed 29 September 2026.
- NHS: When to call 999. Public emergency-care routing and NHS 111 guidance. Accessed 29 September 2026.
The next step should reduce uncertainty, not multiply it.
A useful review identifies priorities, protects appropriate conventional care and makes every test, referral or follow-up decision answer a defined clinical question.